This paper presents an experimental design aimed at enhancing creativity in mathematics among secondary school students. The quasi-experimental research was conducted at two urban secondary schools and one rural school in Hanoi and Nam Dinh provinces, Vietnam, involving 229 grade 6 students and three teachers. The study found that creativity-enriched mathematics instruction, grounded in the principles of realistic mathematics education, such as the use of practical contexts, cultivation of students' experiences, provision of self-initiated and collaborative learning opportunities, and didactic orientation, can foster the development of creative competencies in mathematics. Moreover, the research demonstrates the feasibility and effectiveness of implementing creativity-enriched instruction in various school settings. These findings can help raise awareness among educators and inspire them to modify their teaching methods to promote the development of students' creative competencies, which are increasingly critical in the era of the fourth industrial revolution.